Apparatus for melting metals



'June 6, 193 9. jM R 2,161,180

APPARATUS FOR MELTING METALS Filed April 15, 1957 Patented June 6, 1939 UNITED STATES PATENT OFFICE.

2,161,180 APPARATUS FOR :M'ELTING METALS Peter Marx, Hennef-on-the-Sieg, Germany I Application April 15, 1937,

In Germany April 2 7,

5 Claims.

The invention relates to apparatus for melting metals.

One object of the invention is to provide an improved apparatus for Continuously melting metal in a fuel-fired cupola which is adapted to produce low carbon iron economically, and expeditiously. Heretofore, it has been common to produce low carbon iron by melting and then separately refining it in an electric furnace.

This method involved expensive equipment andhigh operation costs.

The present invention contemplates the melting and refining of the metal in a unitary cupola;

structure which comprises a fuel-fired melting chamber at the lower end of the stack containing the charge and 'a subjacent fuel-fired re-x fining chamber, which receives the 'melted metal from the heating chamber and from which the heat passes to. the melting chamberand the bath in the refining chamber.

Another object of the invention is to provide an improved construction in which the dome of the hearth in the refining chamber is provided with a well for receiving the melted metal from the melting chamber and forming a well in a refractory material which canbe readily i replaced and repaired,

Other objects of the invention will appear from the detail description. I

The invention consists in the several novel features which are hereinafter setforth and are clu'sion hereof. V

In the drawing: Fig. 1 is a-v ertical .section of a cupola furnace embodyingtheinvention. Fig. 2 is a horizontal section taken on line 2-'-2 of Fig; 1. Fig.3 is a section on line 33 of Fig. 1. Fig. 4 is a plan of the refininghearth, its roof being removed. Fig. 5 is a section on'line 5-5 of Fig. 1. Fig. 6 is a vertical section of the heat-exchanger for preheating the liquid fue by means of heated air from the stack.

The cupola furnace comprises a vertical shaft cause it to drop ber. v

in a central opening ,in wall -22. The member more particularly defined by claims at the icon- I ing chamber .Serial N0.137,000

l0 having a refractory-wall, a. smoke-stack H for the products of combustion, supported on top of the shaft, aPnd a base permanently built with the lower endaofthe-shaft III. This base provides a melting chamber l4 below and communieating with the lower end of the shaft l0 and comprises an annular depending side wall 12 and atop-wall 12 having an opening l2 which communicates with the shaft. Suitable burners l3 are adapted to deliver liquid. gaseous, or pulverizedfuel under pressure tangentially into the heating chamber 14 through tangential ducts 16 in the wall l2. The heat from chamber l4 passes through opening l2 into the lower end of shaft III for melting the metal inthe. shaft. A'wall I5 is separate from "and abuts against the bottom of annular wall l2. A conduit or throat-member ll of refractory material is-separately formed from wall 15, is'held in a conical seat 18 in said wall l5 and forms the bottom of the melting chamber-ll. This separability and care of said member and wall 15 which forms thebottom of the heating chamber. Member I! has a central vertical opening Ill-for the passage of heat from a refining chamber 26 under the heating chamber 14 to the melting chamber 14 and for the flow of metalfrom the melting chamber II to the refining chamber 26.

The opening 19 in the member l'l contains openwork refractoryflflwhich permits heat from the refiningchamber .to pass to the melting chamber M and thence to the shaft 10 and at the same time-distributes the melted metal to or trickle to the refining cham-' The member." extends through and fits i1 and wall l5 are mogably and interchangeably supported on a wall 22 whichfoi'ms the roof of .reflningchamber 26. 'Said roof-wall 22 is, togetherwith' the wall is and member 11, supported sb it can belowered awayfrom' the melt- II to provide access to the melting chamber ll and member 11 for care or replacement. Lifting and -suspension devices are provided for raising and lowering and supporting f walls-22, l5 alndmember 11; Each of said devices comprises a manually operablewindl 23, a chain u,

passing around a sheave 25 having one of its ends attached to wall 22 and the hitherto the Windlass. Sheaves 24 andwindlass 23 are supported on any suitable permanent or fixed structure.

'Zl'he' refining chamber 26 is disposed under,

x of the wall li from wall 12! and the separability of member I! from wall l5 facilitate replacement and is separate from, the roof-wall 22 and comprises a hearth 27. and an annularvertical wall roof-wall 22.

or inclined dome 29 which terminates in a top face 30 closely adjacent to the plane of the bottom face of roof-wall 22 and the lower end of linerl1. One or more burners 3| deliver any suitable fuel through tangential ducts 32 into the refining chamber 26 for refining the melted metal.

The upper face of the cone 23 in the refining chamber is provided with a concave well 33 into which the melted metal drips from the refractory l9 -in duct l9. The cleaner portion of the metal descends to the bottom of the well33 and is discharged through ducts 3% onto the side of the dome 29 over which it fiows to the hearth 21 of the refining chamber. The slag accumulates on the top of the metal in the well 3e and is discharged through a channel 35 in the top and side of the cone 29 into an outlet 36 which extends through the wall of the cone so it will pass out'of the refining chamber without flowing to or correspondingly with the melt on the hearth 2'7.

The hearth 21 and well as for the refining' chamber are separable from the roof-wall 23 and are supported on lifting jacks 38 carried by a wheeled truck 31. The jacks 38 are adapted to raiseand-lower the refining chamber and hearth away from and up to the roof-wall 22., When.

lowered away from said wall, the refining chamber can be rolled away on the truck; When the refining chamber has been removed, the walls fractory 39-which is supported in a vertical open- 22 and I5- and-member I I will be supported by the lifting chains 24 and can be lowered away from the melting chamber 54. The burners I5 are supported independently "of' the refining chamber so the latter canrbe raised or lowered and removed while the burners remain imposition. This removability and separability, of the refining chamber and the structure intermediate the melt n chamber l4 and the refining cham-' ber, render all of said parts readily accessible for care, repair or replacement. When the refining chamber is raised by means of jaclns 38, wall 28 of,the defining chamber can be jammed against the roof-wall 22 and the latter will jam the wall l5 against the lower end of wall I lot the melting chamber. This makes it possible to maintain conservation.

The central portion of the dome 29 in the refining chamber in which the well;33 is preferably formed, consistsof a suitable replaceable reing 39* extending through the dome by a gate 48 which is hinged at M and detachably locked in'place by a weighted latch 42 which-is adapted to automatically lock the gate in its raised position and can be swung to release the gate when the refractory 39 is to be removed or replaced.

When the refractory-39 is removed, the residue in-the well 33, heating chamber l4, member 11 and shaft l0 can be removed. A discharge spout. 211. is provided on the refining chamber for drawing off the refined metal; v

A double-walledair-heating jacket 44 in the smoke-stack II is supplied with air under-pres-" sure through pipe 45; which delivers air tangentially into the jacket (Fig. 5). The air is heated in the jacket 44 86 under control of a valve 41 into an annular and is delivered through a pipe header or wind-box 48 around the shaft l0. Pipes 49 deliver the heated air to the burners l5 andend of the shaft I 0. Hot air is also delivered into the upper end of the shaft for additional combusr charging opening 58 .is provided in the upper tion by meansof a branch 59 of hot air pipe 46 and tangential ducts 68 which are supplied with hot air from said branch 59. c

In carrying out the method and operation of the apparatus, the charge of materials to be melted is placed in the shaft l0 through the charging door 58. The lower end of the charge rests on the throat-member i 1 which forms a part .ofthe bottom of the melting chamber l4. Fuel delivered into the chamber M through burners l5 melts the metal at the bottom of the stack and in chamber M. The products of combustion pass upwardly through shaft l0 and to and through the smokestack H. Until melted, the charge will partially rest on the refractory. openwork I98 in the duct IS in member I1. As the charge melts, it will trickle through the openwork refractory l9 into the well 33 in the dome of the refining hearth. The slag will fiow from the top, of the well through duct 35 to the discharge opening 36. The pure metal will iiow from the bottom of well 33 through ducts '34 to the inclined side of the dome 29 and flow onto 2 the hearth and into the bath thereon. The fuel delivered into the refining chamber 26 will heat the metal and refine it. The heat from the refining chamber will pass upwardly through the duct IS in member l! to the melting chamber l4 and from saidchamber to the shaft W. In this manner, the heat from the refining chamber will be utilized in the melting chamber. This method and apparatus are adapted for continuous melt- .ing andrefining. Thismethod involves melting the charge in the melting chamber at the bottom of the stack of the cupola, discharging the melted metal into the fuel-fired refining cham- .ber below the heating chamber and refining the tight connection between these walls for heat metal in the latter chamber.

A characteristic, of the invention is that. the metal froni the melting chamber passes into a well at the top of the refining chamber where the slag is separated from the purer metal and discharged before it reaches the bath in the refining chamber. This is a factor in producing low carboniron because it prevents the metal 'I'heseparate removabflity of the hearth "andside-wall .of the. refining chamber permits the refining hearth'with its dome to be disconnected from the remainder of the cupola and wheeled v away for care or repair. The lifting jacks 38 onthe truck 31 make it possible to securely support the high in' carbon, by eliminating'the slag before the. hearth of the refining roof-wall 22 and intermediate wall IS in closely fitting relation with the wall I abutting against the lower .end of the side wall -I2 of the melting chamber. The removability of the roof-wall 22 5 and the separability .of wall I5 and member II.

from the roof-wall, also facilitate their care and replacement.

The invention is not to be understood as restricted to the detail set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. In a cupola furnace, the combination of a vertical shaft for retaining a charge to be melt- 'ed, a fuel-fired melting chamber under the shaft, a fuel-fired refining chamber communicating with the melting chamber and having a bottom provided with an upstanding dome having a vertically extending opening therethrough and a refractory filling in the opening, a vertical duct leading from the. melting chamber to discharge 5 the melted metal on top of the dome, and a gate under the filling for permitting removal of the,

, refractory from the opening.

2. In a cupola furnace, the combination of a vertical shaft for retaining a charge to be melted, go a fuel-fired melting chamber under the shaft, a fuel-fired refining chamber under the meltin chamber, a vertical duct between the melting and the refining chambers, an upstanding dome on the bottom of the refining chamber disposed un- 5 der the duct so the melted metal will be discharged from the meltingchamber onto the top of the dome and provided with ancpening extending vertically therethrough, and a refractorymaterial in the opening in the dome, and hav- 40 ing a well in the top thereof into which the metal flows from the duct, and a gate under the filling for permitting removal of the refractory.

3. A cupola comprising a vertical shaft adapted to retain the charge to be melted, a fuel-fired melting chamber and a fuel-fired refining chamher, the shaft and chambers being vertically coaxial, the melting chamber being of greater diameter than, and having a horizontal roof extending outwardly from, the lower end of the shaft, said roof being provided with a central opening connecting the shaft and the melting chamber, the refining chamber being of greater diameter than the melting chamber and provided with a horizontally extending roof with a central vertical= opening connecting the refining chamber and the melting chamber, and an upstanding dome in the refining chamber, onto the top of which the metal from the melting chamber flows for distribution in the refining chamber.

4. A cupola comprising a vertical shaft adapted to retain the charge to be melted, a fuel-, fired melting chamber and a fuel-firedrefining chamber, said chambers and shaft being vertically coaxial, a central duct for the melted metal between the melting chamber and the refining chamber, 'the refining chamber having a hearth ing the metal from the melting chamber and separating slag from the metal before it passes to the bath in the refining chamber.

5. A cupola comprising a vertical shaft adapted to retain the charge to be melted, a fuelfired melting chamber and a fuel-fired refining chambensaid chambers and shaft being vertically coaxial, a central duct for the melted metal between the melting chamber and the refining chamber, the refining chamber having a hearth, and an upstanding dome on the hearth which receives the melted metal from the melting chamber, provided with means for separating slag from the metal before it passes to the bath in the refining chamber.

. PETER MARX. 

